In X-ray imaging, when electrical detector units, i.e. detector arrays having a plurality of image forming pixels, like CCD-cells or CMOS-cells are used for transforming the X-ray radiation passed through the object to electrical signal, it is ordinary praxis that at least two, and several if necessary, different detector units are used. The different detector units are typically of different size having a greater or a smaller number of pixels, i.e. various number of X-ray radiation sensitive elements, whereupon the data flow for defining the position of each individual pixel in the detector unit and the actual signal that depends on the received radiation intensity from each individual pixel shall be coupled, which is performed by utilizing a clock frequency, i.e. the data is read from the detector arrays using a multiplexing. The different detector units can also have different other properties requiring e.g. greater or smaller gain or amplification of the output signals, or other deviating electrical settings. When the operating person selects a detector unit for a specific imaging task, it shall be also taken care that the correct clock frequency and the correct gain is selected or activated in the electronic device, typically a computer, to which the detector unit is connected. The operator can of course, do this selection/activation manually, but there is an evident risk that the operator forgets to do this or makes an error by feeding wrong setting.
It is the main object of the invention is to attain a device and/or a method, by which the human errors mentioned above, can be avoided. Accordingly, the intention is to find means to ensure that the correct settings for the individual detector unit selected for use are always fed into the computer, or a respective electronic device, utilized for reading the detector unit. Further object of the invention to attain a device and/or a method, which is as uncomplicated as possible, and could be added in the existing X-ray apparatuses without problems.